Elcavator has developed, tested and verified a completely new technology for electro-hydraulic power transmission in excavators. The main element of the technology is a volume-neutral cylinder. i.e. a hydraulic cylinder that has the same stroke volume in both directions. Volume neutral cylinder is connected with hydraulic pump driven by electric motor with frequency control, so that speed and power on volume neutral cylinder is directly proportional to the torque and speed of the electric motor. When loading, the electric motor runs as a generator and charges the battery.